Conventional protective caps for containers (e.g., aerosol spray paint canisters) are generally configured to press-fit against an upper surface of the container to cover a dispensing valve. To release the contents of the container in a controlled manner, it is necessary to remove the cap to access the dispensing mechanism, such as an aerosol spray button. Generally, the cap is removed by gripping opposing side surfaces and pulling in an upward direction, away from the container base. Alternatively, removal of the cap can be accomplished through the user of a tool, such as a screwdriver. However, removal and attachment of conventional protective caps can be especially difficult and/or painful for various consumers, such as individuals that have limited grip strength or joint pain. Further, the difficulty in removing and/or replacing protective caps is repeated upon each subsequent dispensing of the container contents. It would therefore be beneficial to provide a cap assembly that overcomes the deficiencies of the prior art. In an effort to prevent accidental cap loss or misplacement and to discourage consumer testing of the container contents prior to purchase, it would also be beneficial if the cap assembly includes one or more protective features, such as a lock.